Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Power from Waste Heat Cuts Costs and Emissions

11.06.2012
A new development from Siemens makes it possible for operators of electric arc furnaces to obtain electricity from hot exhaust gases.

Around 20 percent of the electricity required to melt steel scrap could be recovered with the method, according to a report in the latest issue of the research magazine "Pictures of the Future".



Up until now, it has been very difficult to carry out such a process because of temperature and gas-volume fluctuations. Siemens therefore developed a salt storage unit that acts as an energy buffer between a steel furnace and a turbine. The first pilot facility for the system went into operation in the German state of Thuringia in mid-April 2012; the first system product is scheduled to be manufactured in 2013.

Electric arc furnaces melt steel scrap under arcs heated with high-voltage electricity to a temperature of approximately 3,500 degrees Celsius. Such a unit requires around 370 kilowatt-hours of energy per ton of steel produced. The exhaust gases generated in the process can get as hot as 1,700 degrees Celsius. Previously attempted approaches for generating electricity from the gases failed due to fluctuations in gas temperatures and volumes, as steam turbines require a continual flow of steam in a very narrow range of temperatures.

The solution here was taken from the solar-thermal sector - more specifically from Siemens VAI Metals, which uses salt storage units like those employed in such power plants. Here, experts extract heat from the exhaust gas and the salt mixture heats up to around 450 degrees Celsius. Water flows through the hot salt and the resulting steam is used to drive a turbine. The high salt temperature gives the process an efficiency rating of 24 percent, which is greater than that of the second possible option for generating electricity in electric arc furnaces. In this alternative option, steam is produced from the exhaust gas and then stored temporarily in pressurized boilers. However, salt storage units are not only cheaper than such boilers but also safer to operate.

The new solution recovers around 20 percent of the electricity used to run the furnace, which means it also lowers carbon dioxide (CO2) emissions - according to the power mix - by approximately 40 kilograms per ton of steel produced. Given a typical furnace capacity of 120 tons, this results in an annual CO2 reduction of around 30,000 tons. That, in turn, translates into up to five million euros in plant operator savings on electricity and CO2 certificates per year.

Dr. Norbert Aschenbrenner | Siemens InnovationNews
Further information:
http://www.siemens.com/innovationnews

More articles from Power and Electrical Engineering:

nachricht Researchers use light to remotely control curvature of plastics
23.03.2017 | North Carolina State University

nachricht TU Graz researchers show that enzyme function inhibits battery ageing
21.03.2017 | Technische Universität Graz

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Northern oceans pumped CO2 into the atmosphere

27.03.2017 | Earth Sciences

Fingerprint' technique spots frog populations at risk from pollution

27.03.2017 | Life Sciences

Big data approach to predict protein structure

27.03.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>